Let back for pick ratchet looms



Mar. 27, i923- A. PONTZ LETAcK FOR PICK RATGHET LooMs Filed June' e, 1921 @www Patented Mar. 27, 1923.

tra il sfr TSS ADAM roNTz, or READING, PENNSYLVANIA.

l 1 LET BACK' Eo'RrIcx EA'rcHEr' Loolvrs.

' vApplication led June 6,

sists in an improved let-back mechanism for enabling correction of the position of the wheel after failure of the ailing thread and the usual somewhat delayed stoppage of t-he take-up, as fully set forth in connection with the accompanying drawings and clearly dened in the claims.

Fig. 1 is an elevation showing my improved device in operative connection with the ratchet-wheel of a pick-gear; the well known cooperating loom parts being omitted; and the near frame of the machine to which the pawl stops are secured being indicated by dotted lines merely so as to more clearly reveal the essential matter of the invention.

Fig. 2 is a corresponding plan view.

The usual tooth-by-tooth operation of the ratchet-wheel 5, in connection with takeoff and automatic stop mechanisms, is well known, and any setting forth of a particular loom construction apart from such ratchet wheel is unnecessary as my attachment applies merely to said wheel and the adjacent machine framing.

This attachment comprises, as shown, a pawl device 12 having a. shank portion 10 provided with a longitudinal slot 11 in which the extension 6 of the ratchet--wheel axle may be engaged so that the pawl device 12 may freely swing around the wheel axis; the slot permitting of its being projected radially so as to disengage its pawl portion 12 from the ratchet teeth, though such cngagement is normally maintained by a retracting spring 13. A guide projection 14 on said pawl portion 12, extends inward approximately parallel with the sha-nk portion 10, far enough to contact with the other face of the ratchet wheel even when the pawl is projected to tooth-disengaging position; in which latter position it is retained when desired by an offset 15 on the shank portion of the device, which offset 192,1."ser'4ia1No. 475,181.

hereinafter referred to.

l is adapted to engage one of the pawl stops It will bepunderstood that' thistooth-en- Vgaged *pawly device 12 will naturally swing with the wheel 5; excepting as such movement is prevented in the irection of 'feed by an adju'stably fixed vsto-pfas 20; and that y the joint movement of the wheel and pawl in reverse direction, as for let-back, will loel limited by a fixed stop, as 21, having a determined relation to the adjustab-ly `fixed stop'20. This fixed stop 20 merely prevents) the swinging movementy ofv the pawl on the i wheel axis; the swing of the wheel 5 being continued after the pawl 12 has been disengaged from the beveled teeth by the pressing of the pawl outward against the action of spring 13; but the stop 21 will prevent further backward swinging movement of both the pawl and the wheel.

As shown in the construction illustrated asimple bolt hole is required in the adjacent machine frame 4, for passage of a bolt 22, the projecting inner end of which is adapted to serve as stop 21 above referred to; the stop 2O being merely a pawl-supporting projection on a slotted carrier 25, which latter is adjustably mounted `on said fixed bolt 21--22 and locked in position by a nut 23 when it has been set so as to determinedly space-apart the stops 2O and 21.

As indicated in Fig. 1, the ratchet wheel is free to rotate tooth-by-tooth as usual, in

this movement, a determined let-back ofv the wheel and cloth, varying under different conditions, is necessary before laying the fresh filling, so as to produce a uniform texture in the fabric. This required letback is secured by the free reverse movement of the ratchet-wheel together with the pawl device which turns on the same axis; such joint movement however being positively limitedas determined by contact of the pawl device 12--10 with the properly spaced upper stop 21. As this spacing of the upper stop 21 is effected by relative adjustment of the pawl supporting stop 20 of slotted carrier 25, the normal radial position of the pawl device 12-10 being varimay be iXedly located and upper stop 21 be made adjustable instead with ylike effect, the variable spacinglapart of "these stops determining the number of teeth or picks in the let-back.

What I claim is:

l. In combination with a loom havinzgfi a let-back device comprising a radially slidable pawl pivoted upon the -atchet -'vslfheel'A axle and; spring-)retracted into engagement with the ratchet-Wheel teeth', a fixed pawl;

stop secured tov the loom frame,V and arela-f tively adjustablepawl'stop carried v'by said iixed' stop. i

2. In combination Witha` loom having atake-up comprising a` ratchet pick-gear; a-

let-backI device comprising a radially slid;-

ableV pavvl pivoted `lupon the ratchet Wheel-Y aXle'andJ spring-retracted into 'engagementj With the iatcliet-Wheell teeth;Y and ustably spac'ed'paivl-st-o-ps fixed to the 'loomf frameand adapted to determiiiedly limit the joint fand adapted to detei'niinedly limit"the joint -let-baclemovementfof the Wheel and pavvlg saidspring-retractedpawl having an rolf-1 set adapted to engage one of saidfixed stops 1 jvhen the pawlj is* radially projected so as' to disengage the ratchet-Wheel"teeth7 and a guide-projection' adjacent one face of the* :ratchetwheek In testimony 'Whereoff I affix ymy signa# 

